The effect of lactate concentration on the handgrip strength during judo bouts

Judo is a combat sport in which the athletes attempt to hold and control their adversary through gripping techniques (kumi-kata) to apply opportune throwing techniques (nage-waza). Twelve male judo athletes, representing national teams, were recruited to investigate the changes in the maximal isometric strength in both hands before (pre) and after (post) 4 judo bouts and its relationship with the maximal blood lactic acid concentration. The subjects performed a maximal isometric contraction with each hand immediately before and after each bout. A blood sample was taken at 1, 3, and 14 minutes after each bout, and the lactic acid concentration was determined. An overall effect of the successive bouts on the maximal isometric handgrip strength of prebouts was observed for both hands (p < 0.05) but not in that of postbouts (p > 0.05). The dominant hand showed an overall decrease in the maximal isometric strength because of the bout, with the decrease being significant for the first, third, and fourth bouts (p < 0.05). The nondominant hand only showed a significant decrease in the first prebout and postbout (p < 0.05). We observed an inverse relationship between the maximal isometric handgrip strength of postbouts and maximum lactic acid concentration (Lacmax), and between the maximal isometric handgrip strength of postbouts and the lactic acid concentration at minute 14 of the recovery period (Lac14) (p < 0.05). These results show that successive judo bouts significantly reduce the maximal isometric strength of both hands and may suggest that fatigue of each hand depends on different factors. An enhanced understanding of the behavior of the isometric handgrip strength, and the factors that affect grip fatigue during judo bouts in the dominant and nondominant hands, can aid coaches in developing optimal training and exercise interventions that are aimed at mitigating decreases in the capacity of judo athletes to perform a grip.     

Mapping of DNA Sex-Specific Markers and Genes Related to Sex Differentiation in Turbot (Scophthalmus maximus)

Production of all-female populations in turbot can increase farmer's benefits since sexual dimorphism in growth in this species is among the highest within marine fish, turbot females reaching commercial size 3-6?months earlier than males. Puberty in males occurs earlier than in females, which additionally slows their growth. Thus, elucidating the mechanisms of sex determination and gonad differentiation is a relevant goal for turbot production. A ZZ/ZW sex determination mechanism has been suggested for this species, and four sex-related quantitative trait loci (QTL) were detected, the major one located in linkage group (LG) 5 and the three minor ones in LG6, LG8, and LG21. In the present work, we carried out a linkage analysis for several sex-related markers: (1) three anonymous sex-associated RAPD and (2) several candidate genes related to sex determination and gonad differentiation in other species (Sox3, Sox6, Sox8, Sox9, Sox17, Sox19, Amh, Dmrta2, Cyp19a, Cyp19b). We focused our attention on their co-localization with the major and minor sex-related QTL trying to approach to the master sex-determining gene of this species. Previously described growth-related QTL were also considered since the association observed between growth and sex determination in fish. Amh, Dmrta2, and one RAPD were located in LG5, while Sox9 and Sox17 (LG21), Cyp19b (LG6), and a second RAPD (LG8) co-mapped with suggestive sex-related QTL, thus supporting further analyses on these genes to elucidate the genetic basis of this relevant trait for turbot farming.     

Gene Expression Profiles of Spleen, Liver, and Head Kidney in Turbot (Scophthalmus maximus) Along the Infection Process with Philasterides dicentrarchi Using an Immune-Enriched Oligo-Microarray

We evaluated the expression profiles of turbot in spleen, liver, and head kidney across five temporal points of the Philasterides dicentrarchi infection process using an 8x15K Agilent oligo-microarray. The microarray included 2,176 different fivefold replicated gene probes designed from a turbot 3' sequenced EST database. We were able to identify 221 differentially expressed (DE) genes (8.1% of the whole microarray), 113 in spleen, 83 in liver, and 90 in head kidney, in at least 1 of the 5 temporal points sampled for each organ. Most of these genes could be annotated (83.0%) and functionally categorized using GO terms (69.1%) after the additional sequencing of DE genes from the 5' end. Many DE genes were related to innate and acquired immune functions. A high proportion of DE genes were organ-specific (70.6%), although their associated GO functions showed notable similarities in the three organs. The most striking difference in functional distribution was observed between the up- and downregulated gene groups. Upregulated genes were mostly associated to immune functions, while downregulated ones mainly involved metabolism-related genes. Genetic response appeared clustered in a few groups of genes with similar expression profiles along the temporal series. The information obtained will aid to understand the turbot immune response and will specifically be valuable to develop strategies of defense to P. dicentrarchi to achieve more resistant broodstocks for turbot industry.     

Spermatozoa recovery and post-thawing quality of brown bear ejaculates is affected for centrifugation regimes

Sperm cryopreservation protocols for brown bear (Ursus arctos) require the centrifugation of semen samples to increase sperm concentration and to clean urine in contaminated samples. We evaluated the effect of centrifugation regimes (time and relative centrifugal force—RCF) on the quantity of sperm recovered and the quality of post-thawed sperm. Thirteen brown bears were electroejaculated. The ejaculates were diluted 1:1 in Tris–citric acid–glucose (TCG) extender and centrifuged with different RCF/time combinations: 600×g, 1,200×g and 2,400×g, for 3, 6 or 12 min. After centrifugation, spermatozoa were diluted in TES–Tris–fructose extender with egg yolk and glycerol (final glycerol concentration of 8%) and frozen in 0.25-mL straws. In the post-thawed semen, motility was assessed by CASA, and acrosomal status (PNA-FITC), viability (SYBR-14 with propidium iodide) and chromatin status (SCSA) were determined by flow cytometry. The longest centrifugation time (12 min) significantly decreased some motility parameters. Sperm recovery significantly decreased in brown bear at 600×g. Our results suggest that brown bear spermatozoa are more sensitive to long centrifugation times than to high RCF. Centrifugation regimes showed no effects on the post-thawing chromatin status. We recommend preparing the brown bear semen for freezing by centrifugation 1,200×g or 2,400×g for 6 min, after electroejaculation and dilution 1:1 in TCG extender, since these procedures increase the spermatozoa recovery without harmful effects on the post-thawed quality of brown bear spermatozoa.     

Analysis of Malassezia microbiota in healthy superficial human skin and in psoriatic lesions by multiplex real-time PCR

Yeasts from the genus Malassezia are members of the normal biota of human skin, and may play a role in dermatopathology. Our previous study of the fungal microbiota from healthy subjects and from patients with psoriasis using clone library analysis revealed the presence of five Malassezia species and four uncharacterized phylotypes. We now compared the Malassezia microbiota from six healthy body locations and two psoriatic lesions, and evaluated its stability over time using multiplex real-time PCR. Samples from each body location were obtained monthly, for 4 months. Dual-labeled probes were designed to recognize four Malassezia sp. and two uncharacterized groups, and a genus-specific probe was also developed. A good correspondence was obtained between real-time PCR data and clone library analyses. Malassezia restricta was the most abundant species in the majority of samples, and high amounts of Malassezia globosa were also detected. The uncharacterized phylotype 1 was usually detected in lower proportions, nevertheless it was present in most samples. The microbiota was host-specific and relatively stable over time. In accordance with our previous observations, no significant dichotomy between samples from healthy skin and from psoriatic lesions was found; the samples clustered according to the subject, rather than health status.     

Does Environmental Instability Favor the Production and Horizontal Transmission of Knowledge regarding Medicinal Plants? A Study in Southeast Brazil

Greater socio-environmental instability favors the individual production of knowledge because innovations are adapted to new circumstances. Furthermore, instability stimulates the horizontal transmission of knowledge because this mechanism disseminates adapted information. This study investigates the following hypothesis: Greater socio-environmental instability favors the production of knowledge (innovation) to adapt to new situations, and socio-environmental instability stimulates the horizontal transmission of knowledge, which is a mechanism that diffuses adapted information. In addition, the present study describes “how”, “when”, “from whom” and the “stimulus/context”, in which knowledge regarding medicinal plants is gained or transferred. Data were collected through semi-structured interviews from three groups that represented different levels of socio-environmental instability. Socio-environmental instability did not favor individual knowledge production or any cultural transmission modes, including vertical to horizontal, despite increasing the frequency of horizontal pathways. Vertical transmission was the most important knowledge transmission strategy in all of the groups in which mothers were the most common models (knowledge sources). Significantly, childhood was the most important learning stage, although learning also occurred throughout life. Direct teaching using language was notable as a knowledge transmission strategy. Illness was the main stimulus that triggered local learning. Learning modes about medicinal plants were influenced by the knowledge itself, particularly the dynamic uses of therapeutic resources.     

Characterizing the growth of <Emphasis Type="Italic">Sarcoptes scabiei</Emphasis> infrapopulations

The plant stress hypothesis posits that a herbivore’s reproductive success increases when it feeds on stressed plants, while the plant vigor hypothesis predicts that a herbivore preferentially feeds on more vigorous plants. We examined these opposing hypotheses by growing spider mites (Tetranychus urticae) on the leaves of stressed and healthy (vigorous) cucumber plants. Host plants were grown under controlled conditions at low, moderate, and high concentrations of NaCl (to induce salinity stress), at low, moderate, and high fertilizer concentrations (to support growth), and without these additions (control). The effects of these treatments were evaluated by measuring fresh and dry plant biomass, carotenoid and chlorophyll content, antioxidant enzyme activity, and concentrations of PO₄^3?, K⁺, and Na⁺ in plant tissues. The addition of low concentrations of fertilizer increased dry mass, protein, and carotenoid content relative to controls, suggesting a beneficial effect on plants. The highest NaCl treatment (2560 mg L^?1) resulted in increased Na⁺ and protein content relative to control plants, as well as reduced PO₄^3?, K⁺, and chlorophyll levels and reduced catalase and ascorbate peroxidase enzyme activity levels. Analysis of life table data of T. urticae mites raised on leaves from the aforementioned plant groups showed the intrinsic rate of increase (r) for mites was 0.167 day^?1 in control specimens, 0.125 day^?1 for mites reared on plants treated with a moderate concentration of fertilizer (10 mL L^?1), and was highest (0.241 day^?1) on plants grown under moderate salinity conditions (1920 mg L^?1 NaCl). Reproductive success of T. urticae did not differ on plants watered with a moderate concentration of NaCl or a high concentration of fertilizer. The moderately-stressed plants formed a favorable environment for the development and reproduction of spider mites, supporting the plant stress hypothesis.     

Improvement of Brazilian bioethanol production – Challenges and perspectives on the identification and genetic modification of new strains of Saccharomyces cerevisiae yeasts isolated during ethanol process

In Brazil, bioethanol is produced by sucrose fermentation from sugarcane by Saccharomyces cerevisiae in a fed-batch process that uses high density of yeast cells (15–25 % of wet weight/v) and high sugar concentration (18–22 % of total sugars). Several research efforts have been employed to improve the efficiency of this process through the isolation of yeasts better adapted to the Brazilian fermentation conditions. Two important wild strains named CAT-1 and PE-2 were isolated during the fermentation process and were responsible for almost 60 % of the total ethanol production in Brazil. However, in the last decade the fermentative substrate composition was much modified, since new sugar cane crops were developed, the use of molasses instead of sugar cane juice increase and with the prohibition of burning of sugarcane prior harvest. As consequence, these previously isolated strains are being replaced by new wild yeasts in most of ethanol plants. In this new scenario the isolation of novel better adapted yeasts with improved fermentative characteristics is still a big challenge. Here, we discuss the main aspects of Brazilian ethanol production and the efforts for the selection, characterization and genetic modifications of new strains with important phenotypic traits such as thermotolerance.